Directory services for organizing network users into groups are often used in computer network environments. Some directory services include Active Directory, OpenDirectory, eDirectory, and OpenLDAP, among others. Each directory service serves a common purpose of organizing computer users on a network into user groups and organizational units (OUs) depending on a user's role in an organization. Users with the similar policies and organizational roles, such as employees, managers, network administrators, are typically placed into the same user group or OU within the directory service.
Typical items stored within the directory include identities of the users allowed to log into the network, and the computers that are registered within the organization. Each user record, for example, contains many details about the user including the user's computer login name, email address, phone number, user roles within the organization, and full name.
Some directory services are based on a common platform called Lightweight Directory Access Protocol (LDAP), which provides a common method for communication between directory service products developed by different vendors, such as Active Directory (a product by MICROSOFT® Corporation) or eDirectory (a product by NOVELL®, Inc.). Typically, either the internal core of a vendor's directory server implementation is LDAP, or the vendor provides an LDAP networking interface to allow a first directory server to access information contained within a second directory server developed by another vendor.
Due to the fact that directory services contain such detailed information about each user on the network, a directory service becomes a critical source of information to other network services and products on a network that rely on this information to provide network services.